Recharging AC With Propane


As the summer heats up an air conditioning system is a necessity in many climates. [Grayson’s] system suffered some damage over the winter that caused it to vent its refrigerant, avoiding an explosive situation. Before he can chill out inside he’ll need to recharge it and he’s chosen to use propane in his cooling system. According to our friend Google this is not his original idea, but has been done many times before. [Grayson] makes the point that although propane is flammable it’s not necessarily any more dangerous in a fire than Chlorodiflouromethane, or R22, which is the nasty little gas that fled his system for its new home in the upper atmosphere.

The video above includes a brief explanation of recharging the system and the tools needed. We’d need to mill this over for quite a while before working up the gumption to give it a try. For now we’ll stick to [Grayson’s] more pedestrian hacks like making some servo motors sing or easing our yard work woes.

301 thoughts on “Recharging AC With Propane

    1. People with “CREDENTIALS” get freaked out at any threat to their “captive audience” and the high prices
      they get for simple things anyone could do.
      ITS ALWAYS ABOUT POWER AND MONEY not matter they say its about.

    2. Ok, let me get this straight. You’re putting a highly flammable gas (about 4 times as flammable as R22 I understand) in coils that are usually inches above a very hot flame (the furnace if it’s an updraft) under pretty extreme pressure? What could go wrong?

    1. Well, there is no O2 in the refrigerant circuit, so it can’t burn inside the circuit. If it leaks, it will leak slowly, not causing much of a hazard. Even if something weird happens, and it leaks all at once, it won’t be any more dangerous than a propane leak from a stove, dryer, water heater, or furnace, which are kept and operated inside. The highest pressure parts of the AC are outside. So if it’s so dangerous, why do people use propane appliances inside? Methinks you are a R-12 salesman.

      1. 100 % correct .this is what i think too .and by the way all other gases are dangerous rather inhale it or to blow it ,the only friendly gas for all living things is i am with you william ..

      2. Actually you make a lot of assumptions that would get you killed in HVAC. Your ad hominem(attacking the source because you think he’s an R-12 salesman) for pointing out a very real problem doesn’t help your case either. If you think that all leaks are slow then you definitely haven’t worked in HVAC. I mean, simply put you’re saying that propane explosions NEVER happen. Perhaps a simple search would make you rethink your position.

        1. Of course you leave out the little fact that while a massive leak inside the home (and it would need to be a vertical set of expansion coils down stairs) MIGHT raise the LEL of the propane to the point it could actually burn. While on the other hand, if ANY Chlorinated fluorocarbon leaks in the presence of a flame it will produce phosgene gas which is about as lethal as it gets (LDL50 of 350 ppm) so no, the propane fill isn’t much different of a danger than the r22 is. Or the 20 gallons of unleaded in your gas tank etc. etc. But most HVAC people raise hell if anyone suggests using it because they would rather you pay them to come out and charge you anywhere from 300 to 1000% markup on everything they sell you + labor rates of 100 or more per hour. Take a look at how the HVAC lobby got congress to make it illegal to purchase a condenser with R410a even though it is supposed to be environmentally friendly. They want to buy a 4ton condenser for 1200 bucks and the charge their customer around 3 grand to install it in about 2-3 hours tops.

          1. I use Propane or ISO butane frequently on my rentals. As long as you vacuum the machine down to negative atmospheric pressure, and charge to the new correct head pressure under the conversion, it works great. No dangers. One of my hoses burnt to the ground, and no explosion. It was still contained in the unit and needed to be purged in the demo. So all you nay Sayers are restarted. Practice good safety, find your leak, re braes the hole, vacuum down and gauge fill. Thats it, and enjoy the savings and lower electric bill as hydro carbons condence at a lower head pressure. All you doom and gloom types need some schooling in thermal dynamics and chemistry. Also it would be good to point out that LP needs the specific air and fuel ratio too burn period. Worst case of ignition, you would get flashing. Keep up the good work Hackers!

      3. The cabinet is a closed space. Most leaks occur in the evaporator, which is ironically in the cabinet. This is why the amount of r290 allowed in a system is regulated. Door is opened, light goes on, causing a spark, hope someone else looses their eyebrows…the risk is always minimized when you are not taking it.

    2. It is silly arguing over the dangers of a few hundred grams of propane being used in a cars air conditioner, when there are cars driving around on LPG with 20 or so gallons of the stuff in their tanks. Propane has larger molicules than most refrigerants so it does not leak from compressor seals as much, is better for the environment if it leaks and I believe improves the efficiency of AC systems. I can see on big fixed installations how propane could be a major hazard, but cars never spend much time running their AC in confined spaces.

    3. You are clueless or just plain ignorant or both.
      I’ve yet to see a single refinery I’ve helped build or maintain blow up using propane as chiller refrigerants. DAH!

  1. Propane is far more dangerous then R22.

    I think this is no more of a hack then some other inappropriate substitution–is it a hack if I use parallel pieces of lamp cord to wire up some 15A circuits in my house? Sure maybe they have the same current carrying capability, but it’s just not a smart or safe thing to do.

    Good luck w/ the propane… at least the knuckle head isn’t using it to replace the R12 in his old car.

    1. Is it any more dangerous than the gasoline in your car? I’d say not, since the propane won’t stay on your skin, and clothes and keep burning you, even if you get away from the car. You know there is a 10 or 20 gallon tank of it under your back seat.

      1. Car versus house. Not saying the house is any more dangerous. I tend to be doubtful the house is dangerous but… the total turnover of the house air is much slower. than the auto. Getting an explosive concentration of propane in the car cabin is highly unlikely. How about the risk of hitting a bridge abutment? Be afraid, be very afraid. Propane is probably a risk. A tiny risk, In the overall scheme of things, I’d sleep just fine exposing myself and my family to this risk. House central air? I’d want to have a little more info but I doubt it’s enough risk to loose any sleep over. Sincerely, Robert H. Galloway

        1. I already have a bunch of natural gas lines in my house, with 6 different easy-on valves (stove, oven) – and 30 lbs of propane on the back porch.

          The risk of propane in my fridge or HVAC is pretty darn minimal. If the AC leaks propane, at least there is a limited amount available – if my furnace leaks, I get effectively unlimited methane.

    2. This knucklehead did and it works better than the R12 so you don’t know what you’re talking about, you’ve never tried it yet you expect others to follow you by example. Well a ring was never placed in my nose Nor shall I ask anyone follow me. Worry not about that high pressure gas and diesel running through your automobile fuel system or that BIC lighter you have in your pocket DUMOS!

  2. @SS agreed. Also buying quality equipment needed to do a DIY repair (vacuum pump, refill gauges/hose set, torch, solder, pipe, insulation) will far outstrip the cost of having the local pro do it correctly. The only way this is cost effective is if you have to refill multiple times, in which case you’ve got bigger problems…Not to mention the AC compressors are not designed to work with propane (even though it may happen to work)…Personally that’s not a warranty I’m willing to void (and it would probably screw you’re home insurance too).

    1. Most of us have had gauge sets,evacuation pumps, brazing equipment for years. Brazing equipment used for countless other purposes. Equipment used with Freon. Your average guy who considers changing the spark plug in his lawn mower a challenge is not likely to consider substituting propane The cost of using propane is a few dollars worth of fittings to adapt our gauge set to a 20 lb propane tank. I use acetylene in the shop all the time. How explosive is that stuff? Cost of using propane versus some “environmentalist” approved refrigerant in the car is negligible. Cost of using same “Environmentally approved” material versus propane in the house? User has to decide. Additional risk in the house I can live with. Caveat. My in house AC has never lost its refrigerant. It’s still full of R-22 so when the time comes, it it ever does????

      1. you are assuming that propane is a suitable substitute for R-22, yes it can perform the same function as a refrigerant, but FUEL grade propane in not nearly pure enough to use without causing major wear and tear on your system. Refrigerant grade propane (R-290) is compatible with the main oils out there, but has a tendency to degrade natural rubbers and silicon rubbers, so check your hoses frequently for degradation.

        If you attempt to use fuel grade propane your not using pure. they put methane (R-50) and butane (R-600) in there as well and you get an widely varied mixture and in fact may contain some moisture too, which when under pressure and heat can form acids that eat the insulation on compressor windings.

        if your going to do it, do it right, don’t use fuel grade propane, it’s stupid.

        1. Agreed. One wouldn’t be inclined to use freon salvaged from numerous sources of unknown purity. Most of the arguments against this fuel grade propane pertain to damage to the equipment. The owner has to make this decision. The point of the original argument was “Is this dangerous?”

          1. Regular R22 is flammable under the right conditions, just like propane. as long as you get any impurities out of the system like air and moisture before you put it in, it should work. I think the problem people are having with it is the thought of using something that is so highly explosive, it generates a visceral response, “Oh No! Propane in my house!” but this is understandable. alcohol, medicinal or drinking, is in small bottles, lighters carry a very small amount of butane, and camping bottles of propane and grill tanks rarely make it past the garage to the insides of the home. would you ever store paint thinner by your gas water heater? of course not, this mind set is pounded into us at a very early age and that programing kicks in when someone thinks of putting propane in an a/c unit.

            on the topic of salvaging R22, why not? if you are reasonably sure of its purity and contains no acids. When I replace a system, i’m required to reclaim the refrigerant anyway, I test it, if it passes, it goes into my personal collection. most of the time, I’m the one who has maintained it so I know it’s condition. no problem.

            The problem I have with someone doing something like this is simple, it’s hacking vs being a hack. I have no problem with hacking, I do it myself whenever I repair a piece of equipment, and I have the knowledge base to do it right, this insures that it will last a long time and be useful.

            Being a hack though has a definite negative connotation to it, and rightfully so. hacks don’t have the knowledge and can’t be bothered to do the necessary research to do the job right. and in a situation where propane is part of the equation, well, it’s more of a “is he/she dangerous,” question to me.

          2. I have an MACS permit to recycle Freon, also. I wouldn’t hesitate to reuse if I had been the one harvesting and storing. My only reservation would be something about which I had no idea of the history. I think fuel grade propane is of sufficient purity that I wouldn’t be afraid to put it in my car AC

          3. I think that’s what I said. Risk to my system from refrigerant with “GodKnowsWhat” in it, OK. Fear of being blown to kingdom come because somebody used R-290 in a system, particularly an auto AC system is unrealistic. Everybody had to “pays your money and makes your choice”.

          4. this goes back to the quality of service tech comes into question, if they do their job and mark what refrigerant they put into it , and the tech following them knows to check labels for alteration, then I have no worries, but this is kind of why certification is required. but I understand your concern.

          5. If that’s what you think, I can’t dissuade you, I can disagree. you seem to be intelligent enough to have done the necessary research to make that call for yourself, good on you.

            As for the purity of freon? simple, compare it’s pressure to a virgin cylinder of r22 at the same temperature, if they are the same, it’s pure. test it for acid, if it’s clean, it’s good to go.

            Honestly I’m having a hard time reconciling your statements of using propane that may contain moisture in it is ok but using used r22 that you can actually test for acids and purity is not. I would love to learn your thoughts on this.

            Granted this is in your car, question, would you put it in your home?

          6. Not my point, I’m not worried about the safety aspect of it, it’s the ability to develop acids over time, moisture leads to that, put a reclaimed jug of r22 in a freezer to lower the pressure and allow the water to become solid, transfer it to a new evacuated cylinder, but only the liquid. allow it to come to room temperature along side a virgin jug of r22 and compare the pressures. if the pressures are the same, you can be reasonably sure that there aren’t any impurities. if there is, don’t use it, its that simple.

            The problem with propane is that fuel grade has to have impurities to maintain its pressure and is not guaranteed to be moisture free. again putting your system at risk for acid development. If it’s a question of impurity, propane is a greater risk than used r22 that you can test.

    2. Propane also known as R209 when you don’t want the public to know it is propane works very well in automotive air conditioning, and since the molicules are larger the gas does not leak out the seals as fast if at all. You are all worried about a cup full of propane leaking out when LPG fitted cars carry gallons of the stuff without any drama. Many garages sell propane only for car refuelling in remote areas as it saves extra deliveries… Besides LPG is only propane and butane mixed fifty fifty.

      1. Item 1: it’s r-290, there is no r-209, I myself am also dyslexic, but if your going to criticize, you’d best get it right when you do or you end up looking like an idiot.
        Item 2: there is a definite difference between fuel grade propane and r-290,
        a: it IS a mixture of 2 different gasses or more likely 4, all of which condense at different temperatures, and unless charge with liquid, you will be getting an “unbalanced” and likely random mixture into your system. which is sort of like pot luck and anything can happen.
        b: fuel grade propane also contains moisture, which can cause acids to form inside your system, this leads to a faster degradation of the compressor windings.
        Item 3: My problem with it isn’t that someone uses fuel grade or r-290, what concerns me is that someone who takes a short cut and uses fuel grade is likely the sort that won’t bother to document that they have done it. This is going to endanger someone who is unaware of the change. This is what I really have a problem with. I could care less if someone blows them self up as a result of their own stupidity, that’s Darwinian. I have a problem with that person causing someone else to pay the price because they couldn’t be bothered to put a note on the label.

      2. The problem with flammable gas in an automotive air conditioning that isn’t designed for it is that you can easily get a leak into the cabin and that is bad news. it is the same issue with LPG cars a closed parking garages
        I believe the automotive air conditioning that can use flammable gas needs to have a heat exchanger between the evaporator and the air going into the cabin

        1. How are you going to keep that propane at the right density to cause any problems? Even a really fast leak is not going to stay concentrated enough to cause any problems. Most leaks are really seeps that can take months to leak out that itty bitty amount of propane. keep in mind that you only need roughly half as much propane as you do R134. Also consider most leaks don’t occur in the evaporator. They occur in or around the pump itself. Being much heavier than air they flow down to the ground. By the time it reaches the ground on even a bad leak it is already so dissipated you could not get it to burn if you tried.

        1. Propane refrigerators in RVs don’t use propane as the heat exchange cycle. The propane heats an ammonia absorption chiller system which provides the heat exhange. The propane is consumed in these types of systems.

  3. 3 year old system ? I would have contacted the manufacturer. There is no reason a 3 year old system should need more refrigerant unless physically damaged . The lines have to be pressure tested, vacuumed out , refilled with oil, refrigerant replaced and if it wasn’t done in a timely manner when the leak occurred you got bigger problems.

    When refrigerant leaks out that also means moisture is getting in. Adding propane removed any chance of having the manufacturer replace the compressor on failure, which it will , especially on a system that has a leak. The refrigerant will leak out and take the oil with it, moisture will convert the compressor into a rusted block of metal inside.

    1. Moisture in the system will only happen when the inside pressure on the low side gets to be lower than the atmospheric. Adequate evacuation should draw off the moisture. Oil leak should be observable at the site of the leak. One must find and fix the leak before recharging regardless of what is to be used for the recharge. What do you do about moisture and lube leak if you’re charging with an approved refrigerant?

    2. Nice thing with propane that we use in the oil patch is a displacement for water for natural gas systems so we charge them up and fast drain them to atmosphere 2 times so the systems are purged out and i know from many a farmer using equipment they had propane for years in there systems are with peace of mind as the largest systems use average about 14 to 22 ounces not much more than a small standard propane cylinder for a tiny torch

  4. I am a retired professional car mechanic and am certified in AC. Using propane will work, it will also make your car a giant freaking BOMB.
    Let’s say you do this and then you have an accident, the fireman has no clue you’ve made your car a rolling bomb and cuts the wrong thing…BOOM, fireman is now dead and it’s all YOUR fault cause your a tightwad who won’t fix things properly.
    There are countless bad scenarios that can come from this. Who ever wrote this should not be allowed to handle a spoon, much less work on a car.
    Anyone who argues this is not certified as I am and therefore your comments are ignorance based, highly UNSAFE drivel and should be ignored.

    1. I had a dodge caravan AC system high pressure switch stick on me after doing a recharge. It blew the relief valve and filled half the shop with a fog of r134a. If that was a propane blended fuel, I would not be making this post right now. I watched it engulf the heater near the roof as we ran out the door. That would’ve leveled our shop and the neighbor’s building.

        1. The density differences dictate that propane would descend initially, diffusion of gasses would indicate that given a little time, the gas/air mix in the room would become pretty uniform. I’m not convinced that under most uses propane is a dangerous use as a refrigerant but I don’t think the “stays near the floor and away from the ceiling heater” are doing to make the case. The gasoline in the car isn’t under pressure in the passenger compartment. But… When’s the last time you heard of the aircondition system bursting in the passenger compartment and venting its refrigerant. You could be turning the key in the door lock and lightning strike the car. As a practical matter, worry about something realistic.

      1. Truth is it doesn’t matter if it floats or sinks as the amount of propane in the AC system is not enough to reach an explosive level in a shop after a few seconds of leaving the system as it would be too diluted pretty quick. Although you could ignite it near the source after that it would not ignite and definitely could not “level your shop”. For example turn on a propane torch and see how far away you can ignite it from the source. It dissipates pretty fast!

    1. Oh really? Do you even know how to use a multimeter?
      I am a licenced and fully qualified electrician of 40 plus years.I think, somewhere, about 25 years ago, I had a fuse blow in my multimeter. A very rare occurance. Maybe look for another cause.

  5. Density of Chlorodifluoromethane is 3.66 kg/m3 at 15°C. The density of air at sea level is about 1.2 kg/m3.
    My question is; How the hell does one believe that R22 is going to rise into the upper atmosphere? Who cares if ozone gets destroyed? That is what is does. The UV will make more. Duh!

    I’m may be pretty stupid in my own way but seeing the people around me paying for something that is so obviously erroneous just makes me angry.

    I guess there is a sucker born every minute and they must pay for their stupidity. It’s just not right all the profit taking. People’s stupidity hurts me deeply. I feel like I’m living in the dark ages.

    1. Rocks are also considerably heavier than air, and yet small rocks ie sand has been found high up- and before you try saying that must have come down from space they’ve found plant spores/bacteria etc from ground level along with it.

      I think I see your main point- you’re under the impression that less ozone would mean more UV absorption as there’d then be more oxygen for the UV to convert into ozone? That’s half true. Far more UV gets captured when UV encounters ozone, and breaks it down. It’s a reversible reaction catalysed in *both* directions by UV. Free radicals from CFCs/FCs catalyse towards oxygen.

    2. @Angry S. We can tell you’re angry, we can tell you’re no scientist. We can also tell you subscribe to the ostrich theory of education and knowledge in general.

  6. @hmburgers Since when does a hack necessarily have to be safe? You could certainly wire your home with lamp cord and call it a hack, but it wouldn’t be very interesting.

    And on another note, when did the hackaday community become concerned with voiding warranties? I don’t recall that ever being a big concern around here.

  7. So from the posts it sounds like propane is much more flammable. cgmark also pointed out that after the leak, the innards were exposed to the air, and the oil which kept the compressor from getting rusty also may have leaked out. So now we have rust and corrosion which could lead to a spark, we have a flammable refrigerant, and we have a diy recharge where it’s possible some air got in. Even if no air got in, what happens when it leaks again, and he’s grilling out or if the machine clicks on and sparks?
    I just hope he knows what he’s doing for his own safety and the safety of any loved ones.

  8. To those that are complaining about this hack, figure out a better way to fix an AC system yourself. Not everyone lives in an industrialized country. Look at William Kamkwamba and his third world fuse design. Probably not safe enough by our standards, but it gets the job done with limited resources.

  9. While I probably won’t try this myself, I don’t see how it is significantly more dangerous than a system designed to use R290.

    Propane is only explosive in the presence of oxygen and I believe only over a fairly small range of concentration that isn’t likely to exist inside the system, even if there is a leak.

    Since the system wasn’t designed for propane, I can see how efficiency and reliability of the system might be compromised, but what do you expect for a hack?

  10. Did you people even WATCH the video?
    1: His system was damaged by a gigantic chunk of ice freezing it up until it vented the charge. That’s probably voided any warranty right there.
    2: He uses a vacuum pump to evacuate the system to boil off any moisture which leaked in when the system vented, and remove air (and thus O2)
    3: He’s not putting propane (R290 aka R22a) into a CAR, he’s putting it in his HOME heat pump
    4: Propane sold commercially has an added odorant to help locate leaks safely.
    I would NEVER mess with CFC-based refrigerants myself; they’re just outside my comfort zone. But propane, flammable though it is, is well within my capabilities to handle safely. And rather than convert my existing R22 systems to R134a, I will now stronngly consider recharging them with propane instead.

  11. Granted this does work. But there are reasons
    we have licenced trades in North America. If
    his house burns down, his insurance maybe wont pay.
    This the kind of hack you should not have posted..

    1. I disagree, i think this is exactly the kind of hack that should be posted….the idea entered my mind late one night, so i did a google search, discovered and ultimately I viewed this thread. and through viewing the thread, Have decided that yes, I was right, it COULD work, but NO I wouldn’t ever do it. the collective knowledge this thread contains, some good, some bad, some that isn’t categorically knowledge ultimately is as fruitful as asking as many people that this thread contains this question, but a lot more convenient.

  12. @angryScientist:
    Not sure where to begin. Denser gasses will stay lower in the atmosphere but diffusion, weather, and other real world effects will ensure some % of it gets to the upper atmosphere. Halogenated alkanes cause CATALYTIC breakdown of ozone. This means it will continue to destroy ozone as long as it is around. So the same mechanism that has always made ozone (UV) will continue but now concentrations of CFCs have increased the rate of breakdown shifting the equilibrium toward killing us all. Let me know if you want a conversation about evolution being real or climate change not being a conspiracy by scientists…

  13. Why do people think this would be so much more dangerous in a car? I seems to me that the 100+ pounds of gasoline in a car’s fuel tank might be a bigger safety hazard than a couple pounds of propane.

    1. Gas tanks are in the back and protected,(Unless you’re driving a Pinto) and the fuel is in a liquid state – a lot less volatile than gaseous fuel. The condensor in an AC system is in the front of the car, in front of the radiator with little in front of it but plastic. One minor fender bender and you have the potential for a nasty fireball.

      As for using propane in an AC system, most industrial refrigeration units (that don’t use ammonia) use propane, including the diesel powered reefer units that chill semi trailers. (Mainly talking about refrigeration though, not air conditioning)

  14. While it’s not the safest thing in the world, it works incredibly well. As with anything dangerous, just be careful and respect that what you are working with could potentially harm you. About 6 years ago I built a refrigeration system using a 1/4HP compressor and some spare HVAC parts to cool my computer, used propane as the refrigerant, it still works great. loud, but works great.

  15. Certain articles sure seem to provoke near-hysteria on this site.
    AC’s used to use ammonia, and many refrigerators still do. I don’t know that I’d worry about propane any more than I would ammonia.

  16. @Hackineer I agree that charging an automotive A/C system with propane is a bad idea. The trouble is, as @HW pointed out, that, while rescue personnel know that the fuel system of a vehicle is filled with volatile, flammable liquid, they have no reason to expect the A/C system to be charged with a flammable gas.
    Whereas one can vent an R12 system in an emergency without risking a fire, a rescue worker with the jaws-of-life or chop-saw might cut into the system and cause a very intense fire or explosion without any warning.

  17. >But there are reasons we have licenced (sic) trades in North America..

    Which of course have nothing at all to do with unions and trade groups guaranteeing work for themselves by buying themselves a poly-tick or three ;)

    >I am a retired professional car mechanic and am certified in AC. Using propane will work, it will also make your car a giant freaking BOMB.

    Wow, maybe I shouldn’t drive around in my car with 15 gallons of HIGHLY EXPLOSIVE gasoline. Damn, sometimes I even park it inside the house!

    >Anyone who argues this is not certified as I am and therefore your comments are ignorance based, highly UNSAFE drivel and should be ignored.

    Did you take the same open-book, online, 15 minute test that I did to get your chit to work on car AC systems?

    >I disagree. Propane is highly flammable…

    That’s why the only fuel that can be used indoors in forklifts and floor buffers is propane. There’s only a narrow ratio mix with oxygen where the stuff will burn. Propane is wildly popular with the RV crowd for the exact same reason.

    Guys, just wait until they get CO2 refrigeration working half-assed reliability. When that happens, everyone will suddenly realize the awful global warming potential that exists with 1,1,1,2-Tetrafluoroethan (the same stuff used in dust-off and air-horns) and everyone will be forced to upgrade their refrigeration equipment yet again to save the planet as the older gear is phased out. Meanwhile, hydrocarbon based refrigerants will continue to be used in the rest of the world with a reasonable trade off of safety (think a refrigerator with only a few ounces of refrigerant inside)

    BTW, is Snow Peak Giga Power considered fuel, or stealth drop-in blended hydrocarbon R12 replacement?

  18. using propane is not safe if the compressor should fail and the windings short you could have a fire or explosion.

    if you are that tight of a wad that you cant afford the service costs you can.

    1. get your self a bunch of old window air conditioners that are junkers ( hope they still have the charge in them and even run)

    then get the required charge tap to put on the high side of the window air conditioner.

    then with the charge hose you can blow the freon from the junker to the house air conditioner.

    risky because unless you are a licensed refrigeration handler you could be busted for illegal handling although i have heard that the laws seem not to bother with amounts under 50 pounds.

    2. you can charge with r134a also used in dusters and air horns .

    r134a does work but may not as economical you may not get as good of a cost per btu from it.

  19. >a rescue worker with the jaws-of-life or chop-saw might cut into the system and cause a very intense fire or explosion without any warning.

    Hydrocarbon based R-12 refrigerants are (finally) legal for auto AC systems with the proper fittings and labels.

    Piercing an old R-12 system can vent a mist of light oil that can be highly flammable and dangerous in itself.

    Hybrid cars can have high voltages present when turned off. This could be very bad for the untrained rescuers. Should we ban hybrids too?

    It’s all about the balance of risk/rewards. I’m willing to bet the chest x-ray worth of radiation you would have gotten if spread-eagled against the fence on March 1979 in Harrisburg, PA looks a bit less risky than drilling in the gulf nowadays with the benefit of hindsight. Unfortunately, you’ll get the benefits of nether now.

    And we’ll continue to make crappy gasoline substitute at a net energy loss AND crappy sugar substitute out of home-grown subsidized corn while refusing to allow cheaper ethanol imports in the country from overseas, Free Trade and NAFTA and the starving in Africa be dammed.

  20. Gasoline as a liquid doesn’t burn. Neither does propane as a liquid, but it happens to have a very low boiling point. Even if you threw a match in your gas tank, not much would happen. The gasoline vapors above the liquid gasoline would burn if there was sufficient oxygen, but it would quickly suffocate itself. Even if there were enough energy released to sustain a flow of gasoline vapors out the filling portal, it would be anything but an explosion, just a slow burn. In a system containing propane in thin metal pipes, a rupture would quickly lead to a drop in pressure and the boiling of any liquid propane in the system. This also wouldn’t explode, but the sudden release of all of the propane in gas form would create an immediately dangerous situation that could cause a large fireball if there was an ignition source nearby.

    1. If you vented an entire 40 gallon can of propane gas outside anywhere without even a light breeze, you would have trouble getting any kind of an ignition with anything short of a flame-thrower or a blow-torch. Try it sometime.

      The problem with propane is that in an enclosed space, with sufficient oxygen, there is some potential for ignition. This has happened because someone used propane to charge an ac system and didn’t label the system as such. There-in lies the rub.

      Note to self: Don’t smoke a cigarette in an enclosed space after venting an unknown refrigerant into the aforementioned enclosed space.

      Another note to self: If I ever use propane as a refrigerant, maybe make a note of it somewhere, just in case someone other than myself works on it. I’m pretty sure that propane is the future of refrigeration, so probably more and more technicians will be aware of the potentiality of propane in any system and take additional precautions, like ventilating the space, which seems like a precaution that anyone would take. Like I said, someone exploded themselves by smoking a cigarette without ventilating (Australians) after discharging an AC system that contained propane.

  21. ok.
    2nd you have a heat pump, it has a suction line accumulator to store the excess refrigerant in the winter to prevent it from getting to the compressor, so, go nuts with the feeding it liquid.
    3rd r290, as you refer to propane, is compatible with most oils (miscibility is important, you have internal moving parts like reversing valve and the piston metering device at the inside coil) but not POE oil and has a compatibility problem with certain plastics (piston gasket) and rubber (the hoses you use need to be certified compatible with propane).
    4th clean up around your system, damn.
    5th Anyone who thinks that man can affect anything as massively complex as the earths’ climate, has got to belong to the most conceited group of people on the face of the planet.

    sorry for the rant, but when i see stupid, i have to call it for what it is. i guess a lot of people have a problem with it too. and FYI, a few years ago there was a product called maxx fridge, will have to look up the paper i have on it, it’s essentially propane but a different formula suitable as a drop in replacement for any refrigerant, i will post again when i find it.

    otherwise, kudos for making the darwin award wanabe list

  22. My main problem with this hack is that if the leak is inside the house, the propane that escapes could be trapped in a space like the attic awaiting a source of ignition. If the leak is outside it’s not a problem. Does he know where the leak is? Wait, I guess if he did he could just like fix the leak and do it right. OK.

    I’ve seen several articles over the years about charging refrigerators and AC’s with propane instead of Freon, it’s one of those things that comes up every once in awhile especially since the R12 restrictions.

    It’s not an inherently bad idea; as noted upthread some commercial systems use ammonia and I can tell you from personal experience you don’t want to be around when they spring a leak. Thing is, this system is leaky, that’s why he doesn’t want to spring for the Freon to fix it right. This is not a good combination of factors.

  23. For the love of FSM, this guy’s system is practically new and he’s not indicated in any way that it leaks! It’s low on charge because the condenser fan was seized with ice and the pressure shot up enough to trigger the release valve… which immediately closes again. I’m not ready to go do this to my system just yet, but I do recognize that propane is not explosive until it’s mixed with the right amount of oxygen. Even with a bad leak, the worst that’s likely to happen is that the leak point turns into a pilot light or small torch. Yeah, it might start a fire… burn his house down, even. But that’s a far cry from a freaking explosion. Far more likely is that the propane slowly leaks out until the system stops cooling efficiently, just like the original R22. No drama.

    1. Subject of a leak from the indoor portion of a system. I realize the pressure is lower but thousands of rural homes have propane plumbed indoors to the water heater, furnace, kitchen stove, clothes dryer etc,

  24. Couple this with a propane detector in your house and you have a sweet hack. By the way what is up with all of the crap about if the compessor shorts out it can explode and stuff? Get real, you must have a concentration of propane in air that is between the LEL and UEL. Yes there is risk and he accepted it. In most cases of rapid expulsion of the propane will extinguish any spark or cool any ember before it mixes with enough air to ignite so there would be no ignition. Like there is no risk hacking into someones computer? Give me a break! Next thing people will be posting is you shouldn’t post how to hack computers because someone else may actually do it!

  25. lmao this is an epic thread, I suppose that the refrigerator that is in my RV is a bomb too as it came from the factory charged with propane. holy crap people are stupid. Zomg I don’t know anything about it but it sounds dangerous! Think of the Children!

    /literally laughing out loud

  26. Anyone remember freeze12? Propane is just another alternative to some of the expensive refrigerants. As long as the system stays sealed after installing propane, there is no real danger of explosion due to propane’s flammable properties. even if there is a leak, the leak will work like a pilot light if it’s near a spark or a torch if the pressure is high enough. Propane rarely explodes when a leak point in present. If you want a non-flammable replacement for R-12, upgrade to R134a or use freeze12. For R-22, use R417a. If you are fine with propane… use this hack.

  27. focus bob, i said the climate was too big, everything else you mentioned i can’t comment on, but the energies moving our climate system around are far too vast to affect short of man unleashing a nuclear holocaust.

  28. Humm, my car runs on LPG (Propane/Butane mix). Does that mean I’m driving a massive bomb considering I have 60L of LPG in the boot? Oh and I also fill it up myself! Yup, I have a filling port right next to my petrol filler cap that screws on to the bowser hose. Oooh, look! I’m driving around with 130L of explosive fuels!

  29. I have a very old gas stove in my apartment; the pilot lights to out almost every day. I just relight them. I’ve never been blown up. Sometimes they go out while I’m gone for the weekend. When I get back, I relight them. Still haven’t blown up.

    Granted, that’s natural gas instead of propane, but the reason I haven’t blown up is the same: the concentration of the fuel gas with oxygen is not right, and chances are it will never be right.

    We can go round and round about safety and environment all day, but the reality is that you take a big risk every time you get out of bed, and if you really care about the environment, there are a LOT of MUCH BIGGER things you can do to save it. Quit living your lives in fear and misguided indignation.

    1. When you are relighting the pilot I expect you have to press a button down to relight (pressing often sparks a piezoelectric igniter) , and you need to keep that button pressed down for a short down after lighting otherwise the flame will go out again? If so ever thought why? It’s got a thermostatically controlled valve that shuts the gas off when the thermal sensor get’s cold, as it does very quickly without a flame to heat it. If it’s an old stove it wont be using electrical control to do that, but something more like a bimetallic strip, or a capsule of special wax that expands when it gets warm. Holding the “start” button down just bypasses the thermostatically controlled part of the valve, until the valve sensor gets warm enough to keep the valve open.

      1. Not on my old stove in the 90’s the stove was from the 60’s Dutch oven, same with the furnace. they built the house in like 65, I was born in 81. ?Moved to the house in 91 with my mom and stepfather. Any way the original refridgerants were propane. it’s just brining back what they did in 1800. Things I have learned on Vacations while in south Dakota I believe :). Even the new RF 1234YF in my pickup. is really close to propane just one extra atom. hmm makes one wonder

  30. i know somebody that’s done that. no reason it would explode. at the very worst, if a leak ignited you get a little blowtorch action under the hood, which either hits metal, melts plastic, or burns through the fuel lines, THEN you have a problem.

  31. OK, what about you keep the entire propane-refrigerant circuit outside. Use it to refrigerate a water/antifreeze mix, pump that through the wall into the house, blow a fan at a radiator and you’ve got a second heat-exchanger circuit which keeps the heavy, flammable refrigerant all outside in case it leaks.

    Gentlemen, we can rebuild him.

  32. Not all hack’s are safe, but it seems trolling is prevalent on these forums.

    You can make rail guns, high voltage capacitors
    all have the potential to kill you but are good hacks to learn from.

    What happened to the pursuit of knowledge and not the trolling/flaming of forums. There is no need to call people stupid, they are merely misinformed.
    So pass on your knowledge and let them learn.
    Lumen accipe et imperti

  33. Well, fancy that, I was thinking of doing this myself earlier this week.

    and 2nd, has mythbusters looked into this at all?


    I have a deep freezer, 2 fridges and a window A/C unit, what can I do to overclock my Celeron 440 :)

  34. Excuse me, but *what the H3LL* makes anyone think that replacing a non-flammable working medium with a flammable, nay, EXPLOSIVE gas would ever be a good idea?

    Just because you *can* do something, doesn’t mean you *should* do it.

    I’d suggest skipping this experiment if a long and healthy life is part of your long term plans.

    Save the propane for spud guns and barbecues.

    1. My opinion i think was succinct. The total amount of flammable in an automotive air conditioner would be trivial compared with the amount of gasoline in the machine.

        1. Ahhhh the necro police got me. lol So what! It is still on the internet and people still read it. After genius, you commented. No laws or rules against it. Suggest you go have a heart attack somewhere else. cuz here! Nobody really cares.

          1. Sure it is “germane”! The biggest concern 99% of the people here have is that propane is dangerous. However in this application it takes almost half the propane to do the job as it takes R134. On top of that there is very little propane in the system. were you to control burn it you couldn’t even warm up a cup of coffee with it.
            BUT It’s so dangerous! they claim. All the while driving around with highly explosive gasoline routed all over their car within inches of high amounts of heat. The half empty fuel tank is a bomb waiting to happen. Nobody screaming about how dangerous this tiny amount of propane in a completely oxygen free system is taking into account the other hazards involved in driving a vehicle.
            It is ridiculously silly! It is also pointless because, as has been pointed out, Propane has been used for many years in cars and homes in other countries. Personally I won’t heat with NG or Propane because I think propane stoves and hot water tanks are too much of a bother and too dangerous with many cases of them exploding being documented over the years. Yet I would have no problem with an heat pump system that used propane because I know the chances of that system malfunctioning and causing health problems would be nil.

          2. Please pay attention:

            “Excuse me, but *what the H3LL* makes anyone think that replacing a non-flammable working medium with a flammable, nay, EXPLOSIVE gas would ever be a good idea?”

            he asked “what” not “Who”

            It wasn’t germane to this particular part of the comment thread, so get off your soap box and calm down, your point is well made but as I have demonstrated, not actually an answer to WHAT was asked.

          3. My apologies to the grammar/spelling police. However it still addressed the concepts that many are mistaken about.
            Personally I think you should stick to regular refrigerants because apparently your fear of change is hyper-elevated. As is your exaggerated idea that the average homeowner works on his AC system.
            My point was that it would be extremely rare that those “right” conditions would ever occur. If you consider that many new refrigerators already come with propane in them and the other household appliances that are already run on massive amounts of propane or natural gas. Suddenly you are concerned about a relatively miniscule amount of propane in a sealed system. Now if you expressed concern about an r-12 system leaking next to a gas hot water heater I’d be impressed. But all you do is freak out about a system hissing?
            Assuming I lived in a housing development I wouldn’t want my neighbor working on his gas hot water heater without knowing what he is doing. I’d be 100 times more concerned about a hiss coming from a regular propane water heater than i’d ever worry about from an AC system. One reason is that a loud hiss from an AC system is going to last a pretty short time. Remember it takes only roughly half as much propane to do the same job in refrigeration. His hissing hot water heater can level the whole block. Propane has to be the right perfect mixture before it will burn and then it needs an ignition source. If a water heater is hissing it could hiss for days because it has a huge tank hooked to it. If my neighbors system was hissing I’d have to call him and tell him about it. After I called him it would be done leaking out.
            Your priorities of what to fear are totally messed up. You don’t need propane to have dangerous screwups causing explosions. R-22 systems have exploded before due to tech error. In one case the tech barely escaped with his life. Look it up. After analysing all the physics involved I don’t find propane significantly dangerous at all. Mostly for two reasons. 1. the amount used is very small. 2. mixtures have to be just right for propane to actually burn. Getting those conditions just right on accident would be extremely rare.
            Besides it is job security for all techs. Your industry can no lobby for a law to prevent unqualified people from working on their AC systems. I would probably worry more about stupid techs not following procedure. I have spent enough time with various techs to know that many of them barely know anything about the physics behind their own field of work.
            Definitely less dangerous than other stuff being used in cars and homes. Suggest you relax about it.

          4. oh, and the real danger of propane is, as you know, not how it burns slowly and in a controlled situation, but how it can explode under the right conditions, The simple fact that it’s not available in the US yet is because we have a bunch of yahoos going around and doing whatever they want and not being safe about it.

            I went to a class on the safety of hydrocarbon refrigerants and was dismayed with the thought that once they DO get it regulated, a lot of what I just learned would be obsolete or incomplete. I was upset with the fact that I had just wasted my time with the class.

            hypothetical: do you want the owner of the house that is less than 50 feet away from you, soldering his air conditioner lines, not knowing if he has r22 or propane in his system? not evacuating the system before he charges it up from a propane fuel tank? and then running it? what would you do if you heard a loud hiss from it?

            It’s not the smart ones i have a problems with, its with the ones under the dunning-kruger effect.

          5. You seem to be under the notion that I live in fear of this, Indeed, I do not. I AM hyper vigilant in the awareness of my surroundings, the difference being survival in my line of work. I have been a service tech in hvs/cr since the 90’s, so i’ve been at this for a while, and I live in southern indiana, which is replete with individuals who are GLAD to take dangerous short cuts in order to get something working. I have seen people’s house blow up, the richmond hill explosion comes to mind. My point is that it doesn’t take much concentration, the explosive concentration of propane is 2.1%, and if you get above 10.1% there isn’t enough oxygen to sustain an explosion.

            You seem to be under a mistaken notion that I am against hydrocarbon refrigerants in general, I am not, I am against yahoos who don’t know enough NOT to use fuel grade propane. Your lack of knowledge in this field is very effectively displayed in this forum.

          6. I think you need to get back out there and take some physical sciences classes. You are basically knocking a technology because you think some yahoo will screw it up. Stupid rednecks have been screwing stuff up forever. They do it with all kinds of things. If they will do it with their car and their gas water heater then they will do it with their AC whether it has propane in it or not.
            You are such a humanitarian. I am not I guess, since I could care less if the gene pool gets cleared a bit because someone does something stupid. Put a warning label on it and call it good.
            You were defending someone that was saying it was a terrible dangerous idea. When you do that people are going to naturally think you also have those views.
            Oh you think so. And show me a lack of knowledge that I have? So far you haven’t said anything I haven’t known for 20 years. Now you are getting downright trollish.

          7. Thank you for playing “Completely missing the point!”
            1) i have a degree in applied science
            2) i am not knocking the tech, I’m knocking on you because you sounded dumb and I was trying to ascertain your maturity level. The fact that we keep on replying at length with each other should do 2 things, demonstrate that we are both being childish and this is hopefully entertaining to anyone who reads it in the future, they should comment, i’ll be listening.
            3)I am not qualified to say if i am a humanitarian or not, but I am all for self preservation. And now you can blow yourself up so much easier, you might take some innocents with you, THOSE are the ones i care about. heck you might be one of these innocents yourself.
            4)finally, I have a specific question for you:
            do you think it is a good idea for someone to put propane from their grill into their condensing unit?
            please answer with a yes or no

            and as for trolling, yeah, I’ll admit to that, but who was it that answered the wrong question six years after the fact. That’s epic trolling, I bow to your greatness oh mighty troll.

          8. You got issues! Now you want to play list all the degrees we have? Well I could play that too. Which ones you want to count? Does AS count or should we just start at the BS degrees? Sheesh
            And I am knocking on you because you can’t mind your own business.
            I am always entertained by your type of personality. :) lol
            I fundamentally disagree with you. This tech does NOT make it easier to blow yourself up. For one there is nothing really new here. This would actually make it harder. If you really want to blow yourself up you will fill balloons with oxygen and acetylene with a fuse attached. I have never done it but I hear it makes a big bang. Or you could make your own gas from water and fill balloons and put a fuse on it. I have the machines to make hydrogen and oxygen, and I have tanks of acetylene. See? tons easier ways to blow stuff up then messing with propane.
            Finally a real question! A departure from blowhard trolling. But it’s an obvious and stupid question. Grill propane is not clean enough. Nor does it have the right mix of gases. Refrigerant hydrocarbons really should be a 3 gas mix and have to be very pure and clean, totally devoid of any moisture. Well at least if you want your system to last very long. And quite frankly I wouldn’t put it in the evaporative unit either, running or not. Condensing unit? really? I sure hope you aren’t running the system while you pull that little trick.
            You got any more duh style questions? It’s late and you might get lucky.
            Suggest you take your trolling to the fishing hole.

          9. To the “obvious and stupid question,” yes, it was. Thank you for giving the right answer, As to my issues, I invite you to read the 200+ comments in this thread and pay attention to how I have railed against doing just that, as it appears that the person who posted this article seemed to endorse doing so before the video was pulled.

            The fact that you didn’t know my stand on this issue and assume I was asking you because i didn’t know, makes it obvious you didn’t read up most of the other comments here, there are 4 full pages of them, so I wont hold it against you that you didn’t. You probably only caught the last page of comments in your search.

            My stance has ALWAYS been that fuel grade propane is not nearly pure enough to be used in refrigeration, but it has been overshadowed by the “OMG explosive gas” viewpoint. And my issue with the yahoos that do this sort of thing comes from the experience of seeing a system that was not labeled properly if the refrigerant was changed. Documentation is CRUCIAL in this field, I hope you would agree with that.

            Thankfully the only calls I have been on where someone didn’t document necessary information were electrical in nature. I got shocked as a result and pitched a screaming fit at the person who took short cuts, but this just goes to show how some people JUST DON’T KNOW BETTER. Your answer to my question puts YOU in the category of those who DO. Thank you for answering correctly.

  35. Any refridgerant mixed with lubricating oil vapour is flammable, borderline explosive. Without the presence of oxygen in the system it wouldn’t burn until an accident happened and it was released to atmosphere – this tiny amount would come from a small hole and be somewhat like a blow-torch. A little more dangerous, but hardly an explosive fireball from hell waiting to kill you.

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